Disposable absorbent article with selectively expandable or inflatable components

ABSTRACT

A disposable absorbent article having an expandable component is disclosed. The expandable component can be inflatable, and includes a gas evolving material and an activating material separated from the gas evolving material by a breakable barrier. The barrier is broken to combine the materials and inflate the component at the point of use of the disposable absorbent article. The inflatable component can include a spacer for maintaining a fecal void space in a disposable absorbent article.

This is a continuation of application Ser. No. 08/081,733, filed on Jun.23, 1993 now abandoned. This patent application cross-references thefollowing commonly assigned U.S. Patent Applications: U.S. patentapplication Ser. No. 07/898,047, refiled as Ser. No. 08/698,471 on Aug.15, 1996, Spacers for Use in Disposable Absorbent Articles andDisposable Absorbent Articles Having Such Spacers, filed Jun. 11, 1992by Allen et al.; U.S. patent application Ser. No. 07/994,023 now U.S.Pat. No. 5,306,266, Flexible Spacers for Use in Disposable AbsorbentArticles, filed Dec. 21, 1992 by Freeland; and U.S. patent applicationSer. No. 08/081,536, U.S. Pat. No. 5,330,459, Disposable AbsorbentArticle Having an Inflatable Spacer filed on even date herewith by LaVonet al.

FIELD OF THE INVENTION

The present invention is related to disposable absorbent articles havingcomponents that are selectively expandable, such as by inflation, at thepoint of use of the disposable absorbent article.

BACKGROUND OF THE INVENTION

Disposable absorbent articles are well known in the art. Disposableabsorbent articles are used to absorb and retain body exudates, such asurine, fecal material, menses, and the like. A particular desiredfeature of disposable absorbent articles is the capability to acquireand hold body exudates to eliminate, or at least minimize, leakage ofbody exudates from between the absorbent article and the wearer.

References in the prior art disclose a cavity or cutout in the absorbentcore to receive fecal material. The fecal material passes through thetopsheet and is received by the cavity or cutout in the absorbent core.These references suffer from the drawback that a cavity in the absorbentcore decreases its absorbent capacity, and that the cavity is limited involume to the size of the absorbent core. Examples of such teachingsinclude U.S. Pat. No. 2,043,325 issued Jun. 9, 1936 to Jackson, Jr.;U.S. Pat. No. 4,731,065 issued Mar. 15, 1988 to Yamada; U.S. Pat. No.4,834,737 issued May 30, 1989 to Khan; and U.S. Pat. No. 5,062,840issued Nov. 5, 1991 to Holt, et al.

Other references teach adding a spacer to the disposable absorbentarticle. Such spacers can suffer from the drawback that they increasethe thickness and bulkiness of the disposable absorbent article, andthereby increase shipping and storage costs. Such spacers may also beperceived by consumers to be uncomfortable because of their thicknessand bulk prior to application of the diaper to the wearer. Examples ofsuch references include U.S. Pat. No. 5,171,236, issued Dec. 15, 1992 toDreier et al.; U.S. patent application Ser. No. 07/898,047, Spacers forUse in Disposable Absorbent Articles and Disposable Absorbent ArticlesHaving Such Spacers, filed Jun. 11, 1992 by Allen et al.; and U.S.patent application Ser. No. 07/994,023, Flexible Spacers for Use inDisposable Absorbent Articles, filed Dec. 21, 1992 by Freeland.

Still other references disclose absorbent articles having inflatablestructures. French Patent Application 2,561,078 published Sep. 20, 1985in the name of Lefebvre discloses a diaper having a structure which isinflatable by mouth. Such inflation can be awkward or inconvenient,especially in public places or when the diaper is already fastened tothe wearer. Such an arrangement is also disadvantageous because ofsanitary considerations, and because inflation may vary from consumer toconsumer, resulting in over or under inflation of the structure andunpredictable product performance.

U.S. Pat. Nos. 3,881,491 and 3,921,232 issued to Whyte on May 6, 1975and Nov. 25, 1975, respectively, disclose disposable absorbent articleshaving self inflating structures. The self inflating structures includea wall of semipermeable material and a gas evolving material. Uponexposing the outside of the semipermeable wall of the structure to anactivator material, the activator material permeates the structure tointeract with the gas evolving material, whereby the structure becomesinflated by evolved gas. The structure taught by Whyte primarilyprevents core densification and suffers from the disadvantage that itrequires an activator material from an external source (e.g., urine).The wearer may not urinate at the desired time, in the desired location,or in the desired amount to properly inflate the structure. Also,initial inflation of the Whyte structure can separate the gas evolvingmaterial from the semipermeable wall, thereby slowing or stoppingfurther inflation of the structure.

Accordingly, it is an object of the present invention to provide anabsorbent article having a component that is expandable, such as byinflation.

It is a further object of the present invention to provide an absorbentarticle having a component that is inflatable at the point of use of theabsorbent article by a wearer or by a person caring for the wearer,before or after the absorbent article is fastened to the wearer.

It is a further object of the present invention to provide an absorbentarticle comprising an inflatable component, a first material, and secondactivating material separated from the first material by a breakablebarrier which can be broken to combine the first and second materials toinflate the component at the point of use of the absorbent article.

SUMMARY OF THE INVENTION

The invention comprises a disposable absorbent article having atopsheet, a backsheet, an absorbent core disposed intermediate thetopsheet and backsheet, an expandable component, and means for expandingthe component at the point of use of the absorbent article. The meansfor expanding the component include a first material, a second material,and a breakable barrier separating the first and second materials. Thefirst and second materials can be combined at the point of use of theabsorbent article by breaking the barrier. One of the first and secondmaterials can swell or evolve a gas upon combining the first and secondmaterials. The component is thereby expanded from a first thickness tohave a predetermined shape having a second thickness substantiallygreater than the first thickness.

In a preferred embodiment the expandable component is inflatable andincludes one or more inflatable chambers. The inflatable componentincludes a gas evolving material and a liquid impervious breakablepacket containing a liquid activating material. The gas evolvingmaterial and the packet can be disposed in a gas permeable, hydrophobicenvelope. The packet is breakable by the user at the point of use of theabsorbent article to combine the activating material with the gasevolving material. The gas evolved by the combination of the twomaterials inflates one or more inflatable chambers.

In one embodiment the expandable component comprises an inflatablespacer disposed between the topsheet and backsheet. The spacer isinflatable to maintain a fecal void space. In a second embodiment theexpandable component comprises a portion of a seal in which theexpandable component is inflatable to reduce leakage of body exudatesfrom between the absorbent article and the wearer's skin. In a thirdembodiment the expandable component is inflatable to bias a selectedportion of the topsheet into engagement with the wearer.

BRIEF DESCRIPTION OF THE DRAWINGS

While the Specification concludes with claims particularly pointing outand distinctly claiming the present invention, the same will be betterunderstood from the following description taken in conjunction with theassociated drawings in which like reference numerals represent the samecomponent and:

FIG. 1 is a top plan view of a disposable diaper embodiment of thepresent invention, the diaper shown partially cut-away and incorporatingan inflatable keyhole shaped spacer shown in phantom.

FIG. 2 is a top plan view of a disposable diaper embodiment of thepresent invention, the diaper shown partially cut-away and incorporatingan inflatable U-shaped spacer and an inflatable barrier leg cuffcomponent, the spacer and leg cuff component shown in phantom.

FIG. 3 is a cross-sectional view taken along line 3—3 of FIG. 1, withthe spacer joined to an upper layer of the absorbent core.

FIG. 4 is a cross-sectional view taken along line 3—3 of FIG. 1, withthe spacer joined to the backsheet.

FIG. 5 is a top plan view of a keyhole shaped inflatable spacer shownpartially cut-away to show a first gas evolving material and a secondactivating liquid enclosed in a breakable packet.

FIG. 5A is a cross-sectional view of a gas permeable envelope containingboth the gas evolving material and the packet containing the activatingmaterial.

FIG. 6 is a cross-sectional view taken along line 6—6 of FIG. 5 showingthe spacer having a first uninflated thickness.

FIG. 7 is a cross-sectional view taken along line 6—6 of FIG. 5 showingthe spacer having a second inflated thickness, wherein one of the spacerchamber walls is substantially more extensible than the other or ispreformed.

FIG. 8 is a cross-sectional view taken along line 6—6 of FIG. 5 showingthe spacer having a second inflated thickness, wherein both spacerchamber walls deform upon inflation to form a generally oval shapedinflated spacer cross-section.

FIG. 9 is a cross-sectional view taken along line 9—9 of FIG. 2 showingan inflated component comprising a portion of a barrier leg cuff.

FIG. 10 is a top plan view of a sanitary napkin embodiment of thepresent invention shown partially cut-away and having an inflatablecomponent disposed between the backsheet and the absorbent core.

FIG. 11 is a cross-sectional view taken along line 11—11 of FIG. 10showing the inflatable component having a first uninflated thickness.

FIG. 12 is a cross-sectional view taken along line 11—11 of FIG. 10showing the inflatable component having a second inflated thickness.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “absorbent article” refers to devices whichabsorb and contain body exudates, and, more specifically, refers todevices which are placed against or in proximity to the body of thewearer to absorb and contain the various exudates discharged from thebody. The term “disposable” is used herein to describe absorbentarticles which are not intended to be laundered or otherwise restored orreused as an absorbent article (i.e., they are intended to be discardedafter a single use and, preferably, to be recycled, composted orotherwise disposed of in an environmentally compatible manner). A“unitary” absorbent article refers to absorbent articles which areformed of separate parts united together to form a coordinated entity sothat they do not require separate manipulative parts like a separateholder and liner. A preferred embodiment of an absorbent article of thepresent invention is the unitary disposable absorbent article, diaper20, shown in FIG. 1. As used herein, the term “diaper” refers to anabsorbent article generally worn by infants and incontinent persons thatis worn about the lower torso of the wearer. It should be understood,however, that the present invention is also applicable to otherabsorbent articles such as incontinence briefs, incontinenceundergarments, diaper holders and liners, feminine hygiene garments suchas sanitary napkins, and the like.

FIG. 1 is a plan view of the diaper 20 of the present invention in itsflat-out, uncontracted state (i.e., with elastic induced contractionpulled out) with portions of the structure being cut-away to moreclearly show the construction of the diaper 20 and with the portion ofthe diaper 20 which faces or contacts the wearer, the inner surface,oriented towards the viewer. The diaper 20 is shown in FIG. 1 to have afront waist region 22, a rear waist region 24, a crotch region 26, and aperiphery 28 comprising longitudinal edges 30 and front and rear endedges 32. The diaper 20 also has a lateral centerline 34 and alongitudinal centerline 36.

The front waist region 22 and the rear waist region 24 are thoseportions of the diaper 20 which, when worn, encircle the waist of thewearer and are generally the highest elevation of the diaper 20 when thewearer is in the standing position. The crotch region 26 is disposedbetween the front and rear waist regions 22, 24 and is that part of thediaper 20 which, when worn, is between the wearer's legs.

As shown in FIG. 1, the diaper 20 preferably comprises a liquid pervioustopsheet 38, a liquid impervious backsheet 42 joined with the topsheet38, and an absorbent core 44 positioned between the topsheet 38 and thebacksheet 42. The absorbent core 44 can comprise an upper layer 44Ujoined to the topsheet 38 and a lower layer 44L joined to the backsheet42, as shown in FIG. 3. The diaper 20 has an inner surface 39 comprisingthat portion of the diaper 20 which is positioned adjacent to thewearer's body during use (i.e., the inner surface 39 generally is formedby at least a portion of the topsheet 38 and other components joined tothe topsheet 38). The diaper also has an outer surface 43 comprisingthat portion of the diaper 20 which is positioned away from the wearer'sbody (i.e., the outer surface 43 generally is formed by at least aportion of the backsheet 42 and other components joined to the backsheet42.

Referring to FIGS. 1, 3, 5, 6, and 7, the diaper 20 according to thepresent invention also comprises at least one expandable component 200which is expandable from a first thickness T1 (FIG. 6) to apredetermined shape having a second thickness T2 (FIG. 7) substantiallygreater than the first thickness T1. The expandable component 200 cancomprise a spacer 210 disposed intermediate the topsheet 38 and thebacksheet 42 for maintaining a Z-direction fecal void space 211, asshown in FIG. 3. The spacer 210 is preferably expandable by inflation.

The diaper 20 also comprises a means for expanding the spacer 210 at thepoint of use of the absorbent article. The means for expanding thespacer 210 can be activated by the wearer or by the diaperer, andpreferably comprises a means for inflating the spacer 210. Referring toFIG. 5, the means for expanding the spacer 210 comprises a firstmaterial 300 disposed within the spacer 210, a second activatingmaterial 400, and a means for combining the first and second materials300, 400 at the point of use of the diaper 20 to expand the spacer 210from the first thickness T1 to the substantially greater secondthickness T2. The term “point of use” of the diaper 20 refers to thoselocations where the diaper 20 is fastened to the wearer by the diaperer.

The means for combining the first and second materials 300, 400preferably comprises a breakable barrier 490 (FIG. 5) separating thefirst and second materials 300, 400. The breakable barrier 490 cancomprise a breakable packet 500 disposed in the spacer 210 andcontaining the second activating material 400. The wearer or diapererbreaks the packet 500 at the point of use of the diaper 20 to combinethe first and second materials 300, 400, and thereby expand the spacer210. In one preferred embodiment the first material 300 comprises a gasevolving material which generates a gas upon combination with the secondactivating material 400. The evolved gas inflates the spacer 210 fromthe first thickness T1 to the second thickness T2.

Referring to FIG. 1, the diaper 20 preferably also includes a pair oftape tab fasteners 54 positioned in the rear waist region 24 forfastening the diaper 20 to the wearer. The diaper 20 can also havegasket cuffs 56, each comprising a side flap 58 and one or more flapelastic members 60, as well as barrier leg cuffs 62, and a barrier waistcuff 63. The diaper 20 may also include a waist elastic feature, such asan elasticized waist band (not shown). U.S. Pat. No. 3,848,594 issuedNov. 19, 1974 to Buell and U.S. Reissue Pat. No. B1 4,662,875 reissuedMay 5, 1987 to Hirotsu et al. are incorporate herein by reference toillustrate suitable tape tab fasteners 54. U.S. Pat. No. 3,860,003issued Jan. 14, 1975 to Buell; U.S. Pat. No. 4,081,301 issued Mar. 28,1978 to Buell; U.S. Pat. No. 4,695,278 issued Sep. 22, 1987 to Lawson;U.S. Pat. No. 4,808,177 issued Feb. 28, 1989 to Des Marais; and U.S.Pat. No. 4,938,755 issued Jul. 3, 1990 to Foreman are incorporatedherein by reference to illustrate gasket cuffs 56, barrier leg cuffs 62,and a barrier waist cuff 63. U.S. Pat. No. 4,515,595 issued May 17, 1985to Kievit; and U.S. Pat. No. 4,816,025 issued Mar. 28, 1989 to Foremanare incorporated herein by reference to illustrate an elasticizedwaistband for a diaper 20.

FIG. 1 shows a preferred embodiment of the diaper 20 in which thetopsheet 38 and the backsheet 42 have length and width dimensionsgenerally larger than those of the absorbent core 44. The topsheet 38and the backsheet 42 extend beyond the edges of the absorbent core 44 tothereby form the periphery 28 of the diaper 20. While the topsheet 38,the backsheet 42, and the absorbent core 44 may be assembled in avariety of well known configurations, preferred diaper configurationsare described generally in U.S. Pat. No. 3,860,003 issued to Buell onJan. 14, 1975 and U.S. Pat. No. 5,151,092 issued to Buell on Sep. 29,1992, each of which is incorporated herein by reference. Similarly, thefollowing U.S. Patents are incorporated herein by reference for thepurpose of disclosing suitable attachment means for joining componentsof a sanitary napkin: U.S. Pat. No. 4,573,986 issued Mar. 4, 1986 toMinetola, et al.; U.S. Pat. No. 3,911,173 issued Oct. 7, 1975 toSprague, Jr.; U.S. Pat. No. 4,785,996 issued Nov. 22, 1978 to Zieker, etal.; and U.S. Pat. No. 4,842,666 issued Jun. 27, 1989 to Werenicz.

As used herein, the “longitudinal” dimension, direction, or axis of thediaper 20 is aligned front to back with respect to the wearer as thedisposable absorbent article is worn. The “lateral” or “transverse”dimension, direction, or axis of the diaper 20 is orthogonal thelongitudinal direction and is sideways aligned as the diaper 20 is worn.The “Z-direction” is orthogonal to both the longitudinal and transversedirections, and is illustrated in FIG. 3.

The embodiment described herein is suitable for a wearer weighing about7.3 kilograms to about 12.2 kilograms (16 to 27 pounds) and havingischia bones spaced about 3.0 centimeters to about 7.6 centimeters (1.2to 3.0 inches) apart. It will be understood that if the spacer 210 andthe diaper 20 are intended for use with smaller or larger wearers,including adults, the spacer 210 and the diaper 20 can be scaledaccordingly.

The spacer 210 is preferably inflatable from the first thickness T1 tothe second, substantially greater thickness T2. By “substantiallygreater” it is meant that T2 is at least about 10 times, and preferablyat least about 50 times as great as T1. The spacer 210 should have asecond thickness T2 (FIG. 7) in the Z-direction of at least 0.64centimeters (0.25 inch). The thicknesses T1 and T2 are measured under aZ-direction compressive loading of 175 kilograms per square meter (0.25pound per square inch), where the compressive loading is applied over anarea having a circular area of application, or footprint, of about 6.45square centimeters (1.0 square inch). The thicknesses are measured awayfrom the material 300, and the packet 500. The thickness measurement canbe made using a dial indicator such as an Ames Gauge available from theAmes Corporation of Waltham, Mass. Another suitable measurement meansincludes a VIR Electronic Thickness Tester, Model II, available from theThwing Albert Instrument Company of Philadelphia, Pa.

The spacer 210 illustrated in FIGS. 1 and 5 has a generally “keyhole”shape comprising a closed figure. Alternatively, the spacer 210 cancomprise a generally U-shaped figure opening rearward, as shown in FIG.2. In the alternatives shown in FIGS. 1 and 2, the spacer 210 includes alaterally extending portion 220 joining two longitudinally extendingportions 222.

The spacer 210 of FIG. 5 sized for the above mentioned wearers can havean overall longitudinal dimension 212 of about 8.9 to about 11.8centimeters (3.5 to 4.6 inches) and a maximum transverse opening 213 ofabout 1.9 to 3.8 centimeters (0.75 inches to 1.5 inches). Such a spacer210 may also have an overall transverse dimension 214 at the perimeterof the smaller end of the spacer 210 intended for disposition towardsthe front waist region 22 of about 5.1 centimeters (2.0 inches) and anoverall transverse dimension 215 at the perimeter of the larger end ofthe spacer 210 intended to be oriented towards the rear waist region 22of about 9.53 centimeters (3.75 inches). This spacer 210 may have anannular width 216 at the laterally extending portion 220 of about 1.2centimeters (0.5 inches), and an annular width 217 at the longitudinallyextending portions 222 of about 3.2 centimeters (1.2 inches).

The diaper 20 sized to fit the aforementioned range of wearers may bemade having a topsheet 38 with a longitudinal dimension of about 43.8centimeters (17.25 inches) and a backsheet 42 having a longitudinaldimension of about 46.4 centimeters (18.25 inches). The topsheet 38 andthe backsheet 42 according to the present invention may have atransverse dimension, at the crotch region 35, of about 15.9 centimeters(6.25 inch) and about 21.3 centimeters (8.4 inches) respectively.

The difference in dimensions between the topsheet 38 and the backsheet42 foreshortens the topsheet 38 relative to the backsheet 42 creatingthe void space 211 therebetween, even with the absorbent core 44disposed intermediate the topsheet 38 and the backsheet 42. The topsheet38 and upper layer 44U of the absorbent core 44 preferably compriseapertures 46 and 47 respectively. The apertures 46 and 47 are registeredwith one another to provide a passageway for the communication of fecalmaterial from the wearer's anal opening into the void space 211.

As used herein, a “void space” is a cavity intermediate the topsheet 38and the backsheet 42, which cavity is sized to accept fecal material. Avoid space 211 can be closed if the absorbent core 44 is compressedbetween the topsheet 38 and the backsheet 42 by the wearer's weight.When inflated to the have the second thickness T2, the spacer 210 cansupport the wearer's weight and thereby maintain the void space 211 suchthat the void space 211 has a thickness of at least about 0.65centimeters (0.25 inch) and a volume of at least about 16.4 cubiccentimeters (1.0 cubic inches).

Examining the components of the diaper 20 in more detail, the topsheet38 and backsheet 42 are generally coextensive and at least partiallyperipherally joined together. As used herein the term “joined” refers tothe condition where a first member or component is affixed or connectedto a second member or component, either directly, or indirectly, wherethe first member or component is affixed or connected to an intermediatemember or component which in turn is affixed or connected to the secondmember or component.

The topsheet 38 and backsheet 42 may be joined by any means well knownin the art, such as adhesive bonding, ultrasonic bonding or heatsealing. A particularly preferred method of joining the topsheet 38 andbacksheet 42 is using hot-melt adhesive such as manufactured by CenturyAdhesives, Inc. of Columbus, Ohio and marketed as Century 5227; HL1258adhesive sold by the H. B. Fuller Company of St. Paul, Minn.; or FindleyAdhesive H2031 available from the Findley Adhesive Company of Elmgrove,Wis. In a particularly preferred embodiment, adhesive joining isaccomplished by longitudinally oriented adhesive bands or spirals.

As used herein, the term “absorbent core” refers to any component of thediaper 20 used for absorbing and retaining body exudates. The absorbentcore 44 may have opposed major faces and may, if desired, be encased byone or more layers of tissue (not shown), or may be coated with arelease agent to reduce friction against the fecal material.

The tissue layer, if present, improves the tensile strength of theabsorbent core 44 and reduces its tendency to split or clump whenwetted. The tissue layer may further improve transverse wicking offluids and more evenly distribute absorbed liquids throughout theabsorbent core 44. A tissue layer having a basis weight of approximately16 grams per square meter (10 pounds per 3,000 square feet) and an airpermeability of approximately 30 cubic meters per minute per squaremeter (100 cubic feet per minute per square foot) and a differentialpressure of 13 millimeters of water (0.5 inch of water) has been foundto work well.

The absorbent core 44 may be made from a variety of commonly usednatural or synthetic materials, including, but not limited to,comminuted wood pulp, typically referred to as airfelt. If desired, theabsorbent core 44 may further contain particulate or fibrous absorbentgelling materials as is commonly used in the art. In particular, theabsorbent core 44 may be made in accordance with the teachings ofcommonly assigned U.S. Pat. No. 4,610,678 issued Sep. 9, 1986 to Weismanet al.; U.S. Pat. No. 5,137,537 issued Aug. 11, 1992 to Herron et al.;U.S. Pat. No. 4,950,264 issued to Osborn Aug. 21, 1990; U.S. Pat. No.4,834,735 issued to Alemany et al. May 30, 1989; U.S. Pat. No. 5,147,345issued Sep. 15, 1992 to Young et al.; and European Patent ApplicationNo. 0 198 683 published Oct. 22, 1986 in the name of Duenk et al., whichpatents are incorporated herein by reference for the purpose of showinghow to make an absorbent core 44 suitable for use with the presentinvention. Absorbent gelling materials made in accordance with commonlyassigned U.S. Pat. Re. 32,649 issued Apr. 19, 1988 to Brandt et al. havebeen found suitable for use in a diaper 20 according to the presentinvention.

If desired, the lower layer 44L of the absorbent core 44 may havediscrete storage and acquisition zones. The storage zone has a higheraverage density and higher average basis weight than the acquisitionzone, so that the acquisition zone may effectively and efficientlyacquire rapidly discharged liquids and transport the same to the storagezone for long term containment. Such a lower layer 44L may be made inaccordance with above-referenced U.S. Pat. No. 4,834,735.

FIGS. 3 and 4 illustrate an upper layer 44U which is joined to theunderside of the topsheet 38 and a lower layer 44L which is joined tothe upper side of the backsheet 42. The absorbent core 44 haslongitudinal and transverse dimensions generally less than those of thetopsheet 38 and the backsheet 42. The lower layer 44L of the absorbentcore 44 may be made of a variety of sizes and shapes, such asrectangular or hourglass. Of course, a single layer absorbent core 44,as is well known in the art may be utilized.

The upper and lower layers 44U and 44L of the absorbent core 44 may beadhesively joined to the topsheet 38 and backsheet 42, respectively, orjoined thereto by any attachment means well known in the art.Particularly preferred attachment means are adhesive spirals andlongitudinal and transverse bands of adhesive. Particularly preferredtypes of adhesive are manufactured by Century Adhesives, Inc. ofColumbus, Ohio as Century 5227, HL-1258 Adhesive sold by the H. B.Fuller Company of St. Paul, Minn. and XPO-9-035 adhesive manufactured bythe Minnesota Mining and Manufacturing Company of St. Paul, Minn.

Preferably, the lower layer 44L of the absorbent core 44 extends theentire longitudinal dimension of the diaper 20 between the front waistregion 22 and the rear waist region 24, but does not intrude into eitherthe front waist region 22 or the rear waist region 24. The upper layer44U of the absorbent core 44 insulates the wearer from the impressionand applied pressures of the spacer 210, which occur when the wearer issitting while wearing the diaper 20. For this reason, the upper layer44U of the absorbent core 44 should be present at least between the rearwaist region 24 and the aperture 46.

Preferably, the exposed faces of the upper layer 44U and the lower layer44L (those faces not attached to the topsheet 38 or the backsheet 24respectively) are well defined and do not allow a significant quantityof loose fibers to intrude into the void space 211. Intrusion of asignificant quantity of loose fibers into the void space 211 from theabsorbent core 44 could interrupt (if not block) the transport of fecalmaterial in the longitudinal direction, and prevent the isolation ofsuch fecal material from the skin of the wearer.

Referring back to FIG. 1, the “topsheet” refers to any liquid perviousfacing of the diaper 20 which contacts the skin of the wearer while thediaper 20 is worn and prevents substantial contact of the absorbent core44 with the skin of the wearer. The topsheet 38 is preferably compliant,tactilely pleasant and non-irritating to the skin of the wearer.Preferably the topsheet 38 is treated to be hydrophilic, to more readilytransport body exudates to the absorbent core 44.

A suitable topsheet 44 may be manufactured from materials such as porousfoams, apertured plastic films, natural fibers (e.g., wood fibers orcotton fibers), synthetic fibers (e.g., polyester or polypropylenefibers) or a combination of the foregoing. A particularly preferredtopsheet 38 comprises polypropylene fibers having a denier of about 2.2and a length of about 15.9 millimeters (0.62 inches). The topsheet 38may be manufactured according to a number of techniques. For example,the topsheet 38 may be a nonwoven web of fibers spunbonded, carded,wet-laid, meltblown, hydroentangled, combinations of the above, or thelike.

A particularly preferred topsheet 38 is carded and thermally bonded andhas a basis weight of about 18 to about 25 grams per square meter. Asuitable topsheet 38 is marketed by Veratec, Inc., Division ofInternational Paper Company of Walpole, Mass. under the designation P-8.

Alternatively, the topsheet 38 can comprise a formed film. The followingpatents are incorporate herein by reference for the purpose ofdescribing suitable formed films: U.S. Pat. No. 3,929,135 issued toThompson, Dec. 30, 1975; U.S. Pat. No. 4,324,246 issued to Mullane, etal., Apr. 13, 1982; U.S. Pat. No. 4,342,314 issued to Radel, et al.,Aug. 3, 1982; U.S. Pat. No. 4,463,045 issued to Ahr, et al., Jul. 31,1984; and U.S. Pat. No. 5,006,394 issued to Baird, Apr. 9, 1991. Asuitable topsheet for the present invention is formed film described inone or more of the above patents and marketed on sanitary napkins by TheProcter and Gamble Company of Cincinnati, Ohio as “DRI-WEAVE.” Thefollowing documents are incorporated by reference for the purpose ofdisclosing the use of surfactants for treating the topsheet to behydrophilic: U.S. patent application Ser. No. 07/794,745, “AbsorbentArticle Having A Nonwoven and Apertured Film Coversheet” filed Nov. 19,1991 by Aziz, et al.; and above referenced U.S. Pat. No. 4,950,254.

The topsheet 38 can have an elastic panel (not shown) intermediate thelateral axis 34 and the rear waist region 24. Such an elastic panelmaintains the topsheet 38 close to the wearer's skin, and helps tomaintain registration of the aperture 46 with the anal opening. Asuitable elastic panel may be incorporated according to the teachings ofcommonly assigned U.S. Pat. No. 5,032,120 issued Jul. 16, 1991 toFreeland et al., which patent is incorporated herein by reference forthe purpose of showing how to make material suitable for the elasticpanel and incorporate the elastic panel into the topsheet 38, andcommonly assigned U.S. Pat. No. 5,037,416 issued Aug. 6, 1991 to Allenet al., which patent is incorporated herein by reference for the purposeof illustrating a particularly preferred material of construction forthe elastic panel.

Referring to FIGS. 1-2, the aperture 46 is preferably laterally centeredon the longitudinal axis 36. The aperture 46 may be of any shape desiredwith a suitable shape being an oval having a longitudinal dimension ofabout 5.1 centimeters (2.0 inches) and a transverse dimension of about3.8 centimeters (1.5 inches). The rearwardmost edge of the aperture 46is disposed at least about 12.7 centimeters (5.0 inches), and preferablyabout 15.2 centimeters (6.0 inches) to about 21.6 centimeters (8.5inches) from the rear edge 32 of the diaper 20 while it is worn.

It is desirable that the spacer 210 be registered with the apertures 46and 47. A spacer 210 registered with the apertures 46 and 47 spaces apart of the diaper 20 underlying the apertures 46 and 47, such as a partof the absorbent core 44 or backsheet 42, away from the wearer's body.Body exudates, such as solid and liquid fecal matter, can thereby passthrough the apertures 46 and 47 and into void space 211.

Referring to FIGS. 3-4, aperture 47 is aligned with the aperture 46, andpreferably has a shape the same as, or similar to, the shape of aperture46. Preferably, the spacer 210 is registered with the apertures 46 and47, such that spacer 210 does not substantially obstruct aperture 46 oraperture 47, and such that at least a portion of each aperture 46 and 47is disposed intermediate the longitudinally extending portions 222 ofspacer 210.

The backsheet 42 is impervious to fluids, such as urine, and preventsfluids absorbed by and contained in the absorbent core 44 from wettingundergarments, clothing and bedding. As used herein the “backsheet”refers to any barrier disposed outwardly of the absorbent core 44 as thediaper 20 is worn and which contains absorbed liquids within the diaper20. The backsheet 42 is preferably manufactured from a thin plasticfilm, although other flexible liquid impervious materials may also beused. As used herein, the term “flexible” refers to materials which arecompliant and will readily conform to the general shape and contours ofthe human body.

The backsheet 42 may be a polyolefinic film, such as polyethylene,having a thickness of about 0.01 millimeters to about 0.051 millimeters(0.0005 to 0.002 inches). If desired, the backsheet 42 may be embossedor matte finished to provide a cloth-like appearance and may bebreathable. A suitable backsheet 42 can be made from a blend of about 45to 90 percent linear low density polyethylene and about 10 to 55 percentpolypropylene. Suitable backsheet films are sold by Tredegar Industries,Inc. of Terre Haute, Ind. under the designation RR8220 blend for blownfilms and RR5475 blend for cast films; by Clopay Corp. of Cincinnati,Ohio under the designation P18-0401; and by Ethyl Corp., VisqueenDivision, of Terre Haute, Ind. under the designation XP-39385.

Referring again to FIGS. 1 and 5, the spacer 210 can have a keyholeshape comprising a generally closed figure. The closed figure shapeshown in FIGS. 1 and 5 provides the spacer 210 longitudinally disposedso that the end having the smaller lateral width 214 is oriented towardsthe front waist region 22 and the end having the greater transversewidth 215 is oriented towards the rear waist margin 24. This keyholeshape shown in FIGS. 1 and 5 comfortably accommodates the thighs of thewearer, due to the smaller lateral width 214.

The laterally extending portion 220 of spacer 210 is preferably disposedintermediate the front waist region 22 and the aperture 46, and extendsbetween longitudinally extending portions 222. A laterally extendingportion 224 is positioned intermediate the rear waist region 24 and theaperture 46. Other spacer shapes comprising a generally closed figurecan include, but are not limited to, circles, ovals, and polygons.

Alternatively, the spacer 210 can have a shape comprising an openfigure, such as shown in FIG. 2. A laterally extending portion 220 canconnect longitudinally extending portions 222 to form a generallyU-shaped configuration that opens rearwardly. Where the laterallyextending spacer portion 220 is omitted, the spacer 210 in FIG. 2 cancomprise two separate longitudinally extending portions 222 registeredwith the aperture 46.

Referring to FIGS. 5-7, a spacer 210 according to the present inventioncomprises one or more inflatable chambers 230. Inflatable chambers 230can be formed by peripherally joining two chamber walls 232 and 234 atseams 240. A portion of chamber wall 234 is cut away in FIG. 5 to showthe first material 300 and the breakable packet 500 containing thesecond activating material 400, all disposed in an inflatable chamber230. The breakable packet 500 can be broken by the wearer or diaperersqueezing the packet 500 at any desired time at the point of use of thediaper 20.

Seams 240 can include seam extensions 242 for separating adjacentinflatable chambers 230, as shown in FIG. 5. Seam extensions 242preferably extend laterally to provide one or more laterally extendinghinge lines. Such hinge lines reduce the longitudinal stiffness of thespacer 210 when the chambers 230 are inflated. Adjacent seam extensions242 can be spaced apart to provide a channel 244 interconnectingadjacent chambers 230. Channels 244 permit gas generated in one chamber230 to inflate interconnected adjacent chambers 230 so that first andsecond materials 300 and 400 need not be located in each chamber 230.Alternatively, the chamber walls 232 and 234 can be vacuum formed toprovide such hinge lines.

The first and second materials 300 and 400 should be non-toxic andcombine to evolve an inert gas which is non-toxic in the quantitiesgenerated. The first gas evolving material 300 is preferably acombination of a bicarbonate, such as sodium bicarbonate or potassiumbicarbonate, with a powdered acid to provide carbon dioxide when wettedby the second activating material 400. Suitable powdered acids include,but are not limited to citric acid, tartaric acid, terephthalic acid,and salicylic acid. A suitable first material 300 comprises aneffervescent powder containing heat treated sodium bicarbonate, citricacid, and salicylic acid and is available in tablet form from Miles,Inc. of Elkhart, Ind. under the trade name Alka-Seltzer.

The first material 300 is preferably soluble in the second activatingmaterial. The preferred second activating material 400 comprises water.In an alternative embodiment, the first material 300 can comprise abicarbonate and the second activating material 400 can comprise one ofthe above listed powdered acids dissolved in water.

The speed of inflation of the chamber 230 can be controlled by formingthe first material 300 as a fine powder (rapid inflation), or as acompressed tablet (slow inflation). In addition, the first material 300can have a coating that dissolves in the second material 400 to providea time delayed inflation.

Of course, the amounts of first and second materials 300 and 400 willvary depending upon the inflated volume of the chambers 230. The amountsof the bicarbonate and the powdered acid which are mixed to evolve agiven volume of carbon dioxide when dissolved in water can be determinedby stoichiometry. Commonly assigned U.S. Pat. No. 3,881,491 issued toWhyte on May 6, 1975 is incorporated herein by reference for the purposeof showing a method for calculating the amounts of a bicarbonate and apowdered acid which can be mixed to provide a given volume of carbondioxide gas when dissolved in water.

The breakable packet 500 should contain at least enough water or otheractivating second material 400 to dissolve the quantity of the firstmaterial 300 disposed in the chamber. The amount of water required willdepend upon the solubility and quantity of the components of firstmaterial 300. In general, for the bicarbonates and powdered acids listedabove, the packet 500 should contain at least about six milliliters ofwater per gram of first material 300.

The first material 300 can be unconstrained in the inflatable chamber230, or adhesively adhered to one the walls 232 and 234 to prevent thefirst material 300 from shifting during shipping and storage such thatit is not adjacent breakable packet 500. More preferably, the material300 and the breakable packet 500 can be enclosed in an envelope 290comprising a gas permeable material, as shown in FIG. 5A. The gaspermeable envelope 290 is disposed in the chamber 230 and comprises amaterial such as a woven, nonwoven, or apertured film which is permeableto the gas evolved when the first material 300 is combined with thesecond material 400. The gas permeable envelope 290 can be adhered toone of the walls 232, 234. By the phrase “gas permeable material” it ismeant that at least 500 cubic centimeters, preferably at least 5000cubic centimeters, and more preferably at least 50,000 cubic centimetersof the evolved gas at standard temperature and pressure can pass throughsuch a material having a surface area of 6.45 square centimeters (1.0square inch) in one hour when the pressure difference across thematerial is 0.068 atmosphere (1.0 psi) during the one hour interval.

The envelope 290 is preferably hydrophobic, or is treated to behydrophobic. The term “hydrophobic” can be defined in terms of thecontact angle between a liquid and a surface. The American ChemicalSociety Publication “Contact Angle, Wettability, and Adhesion,” editedby Robert F. Gould and copyrighted in 1964 is incorporated herein byreference for the purpose of showing how the contact angle can bedetermined. A surface is hydrophobic for the purpose of this inventionif the contact angle is greater than about 80 degrees, and preferably atleast 90 degrees. A suitable material from which the envelope 290 can beformed is a spunbond hydrophobic polypropylene nonwoven having a fiberdenier between 2.5 and 3.0 and a basis weight between about 16 grams persquare meter and about 30 grams per square meter such as is marketed byFiberweb—North America of Simpsonville, S.C.

The walls 232 and 234 of the inflatable chambers 230 should be gas andliquid impermeable, and are preferably made from a material which issoft and flexible. The inflatable chambers 230 should maintain aninflated thickness T2 of at least 0.635 centimeters (0.25 inch) for atleast one hour, preferably at least three hours, and more preferably atleast six hours when the spacer 210 is subjected to a Z-directioncompressive load of 175 kg per square meter (0.25 pounds per squareinch), and should not completely flatten or rupture when subjected to animpact load such as can result when the wearer sits, or suddenly fallsdown. Suitable materials for walls 232 and 234 include but are notlimited to synthetic thermoplastic films, thermoplastic film/metal foillaminates, natural rubbers, and laminated films of natural rubber andsynthetic thermoplastics. Suitable materials for walls 232 and 234include polyethylene films having a thickness between 0.000635 and0.0127 centimeters (0.25 to 5.0 mils).

One suitable material for making walls 232 and 234 includes apolyethylene film available from Tredegar Industries of Terre Haute,Ind. and designated C-8323 and having a thickness of about 0.028 mm (1.1mil). Such a material has machine direction tensile strength at ruptureof between 790 to 1600 grams/centimeter (2000 to 4000 grams/inch), amachine direction tensile elongation at rupture of between about 400 to700 percent, a cross machine direction tensile strength at rupture ofbetween 390 and 1200 grams/centimeter (1000 and 3000 grams/inch), and across machine direction elongation at rupture of between 400 and 800percent. The tensile strengths and elongations listed above are measuredusing a constant rate of elongation tensile testing machine, such as anInstron Model 1122 made by the Instron Corp. of Canton, Ohio, operatedat an elongation rate of 0.85 cm/sec (20 in/min) with a 2.54 cm (1 inch)sample width and a 5.08 cm (2 inch) gauge length. Another suitablematerial from which walls 232, 234 may be formed comprises anelastomeric film such as a film designated Exx-7 available from theExxon Corporation of Houston, Tex.

One or both of the walls 232 and 234 can be pre-formed, such as byvacuum forming or embossing. Referring to FIG. 7, wall 234 can be vacuumformed to provide a generally semi-circular cross-section upon inflationof chamber 230. Referring to FIG. 8, walls 232 and 234 can be joinedwithout preforming, such that both walls 232 and 234 comprise generallyflat films which deform to provide a generally oval cross-section uponinflation of chamber 230.

The walls 232 and 234 can be joined to form seams 240 by any suitablejoining method such as heat/pressure sealing, adhesive bonding,ultrasonic bonding, or the like. Suitable seams 240 can be formed usinga Vertrod Thermal Impulse Heat Sealer Model 15MGC marketed by theVertrod Corporation of Brooklyn, N.Y.

Referring to FIGS. 3 and 4, the spacer 210 can be joined to the diaper20 by joining one of the walls, such as wall 232, to an underlyingstructure, such as the topsheet 38, backsheet 42, or absorbent core 44.The spacer 210 can be joined to the underlying structure by any suitablejoining method such as heat/pressure sealing, adhesive bonding,ultrasonic bonding, or the like. Suitable adhesives include the Century5227 adhesive and the Findley Adhesive H2031 listed above.

In FIG. 3, spacer 210 is joined to upper core layer 44U. Alternatively,in embodiments not having an upper core layer 44U, the spacer 210, 232can be joined directly to the topsheet 38. In FIG. 4 the lower corelayer 44L is formed around the spacer 210 and the spacer 210 is joinedto backsheet 42. In an alternative to the embodiment shown in FIG. 4,chamber wall 232 can comprise a portion of backsheet 42, and wall 234 isjoined directly to the backsheet at the seams 240.

Referring to FIG. 5, the breakable packet 500 can be formed byperipherally joining two flexible walls 532 and 534 along seams 540. Aportion of the wall 534 is cut away in FIG. 5 to show the secondmaterial 400 contained in the packet 500. The two walls 532 and 534 canbe formed from a liquid impervious plastic film, such as a polyethylene,polypropylene, or polyester film. The two walls 532 and 534 can begenerally rectangular, and can be peripherally joined along 3 sides toform a pocket. The pocket can be partially filled with the secondactivating material 400 (e.g., water). The fourth side of the walls 532and 534 can then be sealed along a seam 540 to close the pocket andcontain the water. The pocket so formed is preferably only partiallyfilled such as to about 80 to 90 percent capacity to prevent thebreakable packet 500 from inadvertently rupturing during packaging orshipping.

The two walls 532 and 534 can be joined at seams 540 by any suitablemethod such as by heat/pressure sealing, adhesive bonding, ultrasonicbonding, or the like. Suitable seams 540 can be formed using the VertrodModel 15MGC heat sealer listed above.

The wearer or diaperer inflates the spacer 210 by breaking the packet500 prior to fastening the diaper 20 on wearer, such as by squeezing theportions of the diaper 20 overlying and underlying the packet 500between the thumb and forefinger. The packet 500 can be located suchthat it can be squeezed and broken before or after the diaper 20 isfastened to the wearer. The envelope 290 holding the packet 500 can bejoined to chamber wall 232 (or to the backsheet 42 if chamber wall 232comprises a portion of backsheet 42) such that the packet can be easilyaccessed for squeezing between portions of the backsheet 42 eitherbefore or after the diaper 20 is fastened on the wearer.

In an alternative embodiment the packet 500 can be disposed in one ofthe front and rear waist regions 22, 24 so that it can be easilyaccessed before or after the diaper 20 is fastened to the wearer. Forinstance, the packet 500 and first material 300 can be disposed in achamber in one of the front and rear waist regions 22, 24. The chambercontaining the packet 500 and first material 300 can be fluidlyconnected to an inflatable chamber 230 by a slender tube. The chamber inthe waist region 22, 24 and the slender tube can be formed by extensionsof flexible chamber walls 232, 234.

The breakable packet 500 can be weakened to break along a predetermineddirection so that the second activating material 400 is directed towardthe first material 300. Referring to FIG. 5, the packet 500 can includea nozzle 542 formed by reducing the width of a seam 540 adjacent thefirst material 300. The nozzle 542 directs the activating material 400in the packet 500 toward the first material 300. Alternatively, thepacket walls 532 and 534 can be formed from a material having adifferent tensile elongation at rupture along two mutually perpendiculardirections.

The direction 552 is parallel to the machine direction of the materialfrom which walls 532 and 534 are formed, and the direction 554 isparallel to the cross machine direction of the material from which walls532 and 534 are formed. The machine direction tensile elongation atrupture is preferably significantly lower than (e.g., less than half)the cross machine direction elongation at rupture, so that the walls 532and 534 rupture along a tear line parallel to the cross machinedirection (direction 554). The opening so formed can direct at leastsome of the second material 400 toward the first material 300.

A suitable material for forming packet walls 532 and 534 and having amachine direction tensile elongation at rupture which is between about ⅓and ½ the cross machine direction tensile elongation at rupture isavailable from Tredegar Industries of Terre Haute, Ind. under thedesignation C-8570 and having a thickness of about 0.028 mm (1.1 mil).Such a material has machine direction tensile strength at rupture ofbetween 590 and 1400 grams/centimeter (1500 to 3500 grams/inch), amachine direction elongation at rupture of between about 100 to 300percent, a cross machine direction tensile strength at rupture ofbetween 400 and 790 grams/centimeter (1000 and 2000 grams/inch), and across machine direction elongation at rupture of between 300 and 700percent. The tensile strengths and elongations listed above are measuredusing a constant rate of elongation tensile testing machine, such as anInstron Model 1122 made by the Instron Corp. of Canton, Ohio, operatedat an elongation rate of 0.85 cm/sec (20 in/min) with a 2.54 cm (1 inch)sample width and a 5.08 cm (2 inch) gauge length.

By way of an example, an inflatable spacer 210 having the abovementioned dimensions and formed from the above mentioned Tredegar C-8323can be inflated to a thickness T2 of about 1.27 centimeters (0.5 inch)with about 300 mg of Alka-Seltzer and about 4.0 ml of water in packet500.

Referring to FIGS. 2 and 9, the diaper 20 can include an expandablecomponent 200 comprising a seal member 600 (shown in phantom in FIG. 2).The seal member 600 comprises a portion of a seal means for reducingleakage of body exudates from between the diaper 20 and the wearer'sskin. Such a seal means can comprise a barrier leg cuff 62 for reducingleakage from between the diaper 20 and the wearer's legs in the crotchregion 26. Such a seal means can also comprise a barrier waist cuff 63for reducing leakage from one of the front and rear waist regions 22,24. Above referenced U.S. Pat. No. 4,938,755 is incorporated herein byreference for the purpose of showing a suitable construction for thebarrier cuffs 62 and 63. The seal member 600 will be described as itcomprises a portion of a barrier leg cuff 62, it being understood thatthe following description can be easily adapted to provide a seal member600 comprising a portion of a barrier waist cuff 63 shown in phantom inFIG. 2.

The barrier leg cuff 62 has a proximal edge 64 joined to a side flap 58in the crotch region 26 and a longitudinally extending distal edge 66which is not attached to an underlying diaper structure in the crotchregion 26. The barrier leg cuff 62 may include an elastic spacingelement 61 operatively associated with the distal edge 66 for spacingthe distal edge 66 apart from the topsheet 38.

Referring to FIG. 9, the barrier leg cuff 62 has oppositely facingoutward and inward surfaces 65, 67 extending between the proximal anddistal edges 64, 66. The inward surface 67 faces an underlying diaperstructure, such as topsheet 38. The seal member 600 is joined to theinward face 67 and is expandable to space the distal edge 66 apart fromthe topsheet 38. A channel 80 for receiving and holding body exudates isthereby formed between the barrier leg cuff 62 and the topsheet 38. Thebarrier leg cuff 62 shown in FIG. 9 comprises both the seal member 600and an elastic spacing element 61. Alternatively, the elastic spacingelement 61 can be omitted.

The seal member 600 is preferably inflatable and comprises at least oneinflatable chamber 630 disposed intermediate the proximal and distaledges 64, 66. The inflatable chamber 630 can be formed between chamberwalls 632 and 634 peripherally joined together at seams 640. Suitablematerials for forming chamber walls 632 and 634 include those materialslisted above for forming chamber walls 232 and 234. Seams 640 can beformed similarly to seams 240 described above. Chamber wall 632 can bejoined to the inward surface 67 of the barrier leg cuff 62 by anysuitable method such as heat/pressure bonding, adhesive bonding, orultrasonic bonding, to secure the expandable component 600 to thebarrier leg cuff 62.

The inflatable chamber 630 can comprise a generally longitudinallyextending portion 652 and at least one generally laterally extendingportion 654. The generally longitudinally extending portion 652 can begenerally parallel to and juxtaposed with the proximal edge 64 of thebarrier leg cuff 62. Referring to FIG. 2, the longitudinally extendingportion 652 preferably extends into at least one of the front and rearwaist regions 22, 24.

The first material 300 and the breakable packet 500 containing thesecond activating material 400 can be enclosed in a gas permeableenvelope 290 (FIG. 5A) disposed within the longitudinally extendingportion 652 and positioned in one of the front and rear waist regions22, 24. The breakable packet 500 is positioned in the front waist region22 in FIG. 2. Positioning the breakable packet 500 in one of the frontand rear waist regions 22, 24 permits the wearer or diaperer to easilyaccess and rupture the breakable packet 500 before or after the diaper20 is fastened to the wearer.

The laterally extending portions 654 can extend intermediate thelongitudinally extending portion 652 and the distal edge 66 of thebarrier cuff 62. The laterally extending portions 654 can beinterconnected by the longitudinally extending portion 652 such thatportions 652 and 654 can be inflated by breaking a single packet 500.The chamber wall 634 can be preformed, such as by embossing or vacuumforming the chamber wall 634, such that the inflated thickness ofportion 652 of inflatable chamber 630 is smaller than the inflatedthickness of portions 654 of inflatable chamber 630.

Inflation of the laterally extending portions 654 causes chamber wall634 to abut topsheet 38, and thereby bias the distal edge 66 apart fromthe topsheet 38. Because the inflated thickness of the longitudinallyextending portion 652 is smaller than the inflated thickness of thelaterally extending portions 654, body exudates can flow betweenadjacent laterally extending portions 654 and be held in thelongitudinally extending channel 80 formed between the barrier leg cuff62 and the topsheet 38.

In the embodiments described above, the expandable component 200 isinflatable, and the first material 300 evolves gas upon combination withthe second activating material 400. In an alternative embodiment, thefirst material 300 can comprise a material that swells or expands uponcombining with, or being wetted by, the second activating material 400.For example, first material 300 can comprise a number of absorbentmaterials, including but not limited to absorbent foams, absorbentgelling materials, or superabsorbent polymers which swell or expand uponbeing wetted. A suitable superabsorbent material for use as the firstmaterial 300 is disclosed in U.S. Pat. No. 4,610,678 issued Sep. 9, 1986to Weisman, et al.

The diaper 20 is applied to the wearer by positioning the back waistregion 24 under the wearer's back and drawing the remainder of thediaper 20 between the wearer's legs so that the front waist region 22 ispositioned across the front of the wearer. The ends of the tape tabfasteners 54 are then secured, preferably to outward facing areas of thediaper 20.

SANITARY NAPKIN EMBODIMENT

Referring to FIGS. 10-12, a disposable absorbent article according tothe present invention can comprise a sanitary napkin 720. As usedherein, the term “sanitary napkin” refers to an absorbent article whichis worn by females adjacent to the pudenal region, generally external tothe urogenital region, and which is intended to absorb and containmenstrual fluids and other vaginal discharges from the wearer's body(e.g., blood, menses, and urine). Interlabial devices which residepartially within and partially external of the wearer's vestibule arealso within the scope of this invention. As used herein, the term“pudendal” refers to the externally visible female genitalia. It shouldbe understood, however, that the present invention is also applicable toother feminine hygiene or catamenial pads such as pantiliners, youth andadult incontinence pads, and the like.

The sanitary napkin 720 has a body contacting surface or body surface721 and an oppositely facing garment surface 723. The sanitary napkin720 is shown in FIG. 10 as viewed from its body surface. The sanitarynapkin 720 has a longitudinal centerline 736 and a lateral (ortransverse) centerline 734. The term “longitudinal” as used inconnection with the sanitary napkin 720 refers to a line, axis, ordirection in the plane of the sanitary napkin 720 that is generallyaligned with (e.g., approximately parallel to) a vertical plane whichbisects a standing wearer into left and right body halves when thesanitary napkin 720 is worn. The terms “transverse” and “lateral” areinterchangeable as used in connection with the sanitary napkin 720 andrefer to a line, axis, or direction which lies within the plane of thesanitary napkin 720 that is generally perpendicular to the longitudinaldirection. The Z-direction (FIG. 12) is generally orthogonal to both thelongitudinal and lateral centerlines 736, 734. The sanitary napkin 720has a periphery defined by longitudinal side edges 730 and lateral endedges 732.

Portions of the structure of the sanitary napkin 720 are shown cut awayin FIG. 10 to more clearly show the construction of the sanitary napkin720. As shown in FIG. 10, the sanitary napkin 20 preferably comprises aliquid pervious topsheet 738, a liquid impervious backsheet 742 joinedwith the topsheet 738, and an absorbent core 744 positioned between thetopsheet 738 and the backsheet 742.

The sanitary napkin 720 further comprises an expandable component 200, afirst material 300, and a second activating material 400 separated fromthe first material 300 by a breakable barrier which can comprise abreakable packet 500. The expandable component 200 preferably comprisesan inflatable component 800 having at least one inflatable chamber 830.The first and second materials 300, 400 can be disposed in theinflatable chamber 830.

The inflatable component 800 is preferably juxtaposed with the backsheet742, and can be joined directly thereto. Referring to FIGS. 11 and 12,the inflatable component 800 is preferably disposed between thebacksheet 742 and the absorbent core 744. FIG. 11 shows across-sectional view of the sanitary napkin 720 taken along section line11—11 of FIG. 10 prior to inflation of the inflatable chamber 830. FIG.12 shows a similar cross-sectional view of the sanitary napkin 720 afterthe breakable packet 500 is ruptured and the first and second materialscombine to inflate chamber 830. The inflation of chamber 830 spacesoverlying portions of the absorbent core 744 and topsheet 738 apart fromthe backsheet 742 in the Z direction. The inflation of chamber 830thereby biases a portion of the topsheet 738 into engagement with thewearer's external genitalia for improved body fit, and to moreeffectively transfer fluid exudates to the absorbent core 744.

While the topsheet 738, backsheet 742, and absorbent core 744 may beassembled in a variety of well known configurations (including so calledtube products or side flap products), preferred sanitary napkinconfigurations are described generally in U.S. Pat. No. 4,950,264 issuedto Osborn on Aug. 21, 1990; U.S. Pat. No. 4,425,130 issued to DesMaraison Jan. 10, 1984; U.S. Pat. No. 4,321,924 issued to Ahr on Mar. 30,1982; and U.S. Pat. No. 4,589,876 issued to Van Tilburg on Aug. 18,1987. These patents are incorporated herein by reference. FIGS. 10-12show a preferred embodiment in which the topsheet 738 and the backsheet742 have length and width dimensions larger than those of the absorbentcore 744, and extend beyond the side and end edges 745, 747 of theabsorbent core 744.

In use, the sanitary napkin 720 can be held in place by any supportmeans or attachment means (not shown) well-known for such purposes.Preferably, the sanitary napkin is placed in the user's undergarment orpanty and secured thereto by a fastener such as an adhesive. Theadhesive provides a means for securing the sanitary napkin in the crotchportion of the panty. Thus, a portion or all of the garment surface 723of the backsheet 742 can be coated with adhesive. A pressure-sensitiveadhesive is preferred. Suitable adhesives are Century A-305-IVmanufactured by the Century Adhesives Corporation of Columbus, Ohio;Instant Lock 34-2823 manufactured by the National Starch and ChemicalCompany of Bridgewater, N.J. Suitable adhesive fasteners are alsodescribed in U.S. Pat. No. 4,917,697. The pressure sensitive adhesive istypically covered with a removable release liner in order to keep theadhesive from drying out or adhering to a surface other than the crotchportion of the panty prior to use. Suitable release liners are alsodescribed in the above-referenced U.S. Pat. No. 4,917,697. Non-limitingexamples of commercially available release liners are BL30MG-A SiloxE1/0 and BL30MG-A Silox 4P/O, both of which are manufactured by theAkrosil Corporation of Menasha, Wis. The sanitary napkin 720 is used byremoving the release liner and placing the sanitary napkin 720 in apanty so that the adhesive adheres to the panty and maintains thesanitary napkin 720 in the desired position within the panty during use.

The sanitary napkin 720 may also have two flaps (not shown) each ofwhich are adjacent to and extend laterally from the side edge 745 of theabsorbent core 744. The flaps are configured to drape over the edges ofthe wearer's panty in the crotch region so that the flaps are disposedbetween the wearer's panty and the thighs. The flaps help preventsoiling of the wearer's body and garments, and are preferably providedwith attachment means so that the flaps can be folded back under thepanty and be attached to the garment facing side of the panty. The flapsthereby maintain the sanitary napkin 720 and the inflatable component800 in proper registration with the externally visible female genitalia.The following patents are incorporated by reference for the purpose ofshowing flaps suitable for use with sanitary napkins of the presentinvention: U.S. Pat. No. 4,687,478 issued to Van Tilburg, Aug. 18, 1987;and U.S. Pat. No. 4,608,047 issued to Mattingly, Aug. 26, 1986.

Referring to FIGS. 11 and 12, the inflatable chamber 830 can be formedby peripherally joining two flexible chamber walls 832 and 834 alongseams 840. A portion of the chamber wall 834 is shown cut away in FIG.10 to show the first material 300 and the breakable packet 500 disposedwithin the inflatable chamber 830. The first material 300 and the packet500 can be disposed in a gas permeable envelope 290, as shown in FIG.5A. Chamber walls 832, 834 can be formed from the same materialsdescribed above for forming chamber walls 232, 234 of expandingstructure 200, and seams 840 can be formed in the manner described abovefor seams 240.

The inflatable component 800 is joined to the backsheet 742 by anysuitable attachment means well known in the art. For instance, chamberwall 832 can be joined to the backsheet 742 by heat/pressure bonding,ultrasonic bonding, or by adhesive bonding. A suitable adhesive forjoining the inflatable component 800 to the backsheet 742 includesCentury Adhesive 5227 listed above. Alternatively, the chamber wall 832can comprise a portion of the backsheet 742, and the chamber wall 834can be joined directly to that portion of the backsheet 742 along seams840.

The inflatable chamber 830 as viewed in FIG. 10 can comprise a number ofshapes including, but not limited to, closed figures, open figures,ovals, squares, circles, straight segments, and curvilinear segments. Ina preferred embodiment, the inflatable chamber 830 comprises at leastone longitudinally extending portion 860. The inflatable chamber 830 canalso comprise at least one, and preferably a plurality of laterallyextending portions 862. The laterally extending portions 862 should belongitudinally spaced apart as shown in FIG. 10 to provide longitudinalflexibility. Spacing the laterally extending portions 862 apart in thelongitudinal direction enhances bending of the sanitary napkin 720 aboutaxis 734. The laterally extending portions 862 are preferablyinterconnected with the longitudinal extending portion 860 so that onlyone packet 500 is needed to inflate chamber 830. The laterally extendingportions 862, when inflated, increase the lateral bending stiffness ofthe sanitary napkin 720 about axis 736, and help to prevent lateralcrushing of the sanitary napkin 720 between the wearer's legs.

Referring to FIG. 1, the longitudinally extending portion 860 has alength 811 greater than its width 812. Each laterally extending portion862 has a length 814 greater than its width 813. Referring to FIG. 12,the chamber wall 834 is preferably pre-formed, such as by embossing orvacuum forming, such that upon inflation of the chamber 830, thelongitudinally extending portion 860 has an inflated thickness greaterthan the inflated thickness of laterally extending portions 862. Thelongitudinally extending portion 860 can thereby bias a portion of thetopsheet 738 to fit against the external genitalia of the wearer.

The longitudinally extending portion 860 is shown generally colinearwith the longitudinal axis 736 in FIG. 10. Inflation of thelongitudinally extending portion 860 thereby biases the portion of thetopsheet 738 aligned with centerline 736 to fit against the externalgenitalia of the wearer. In an alternative embodiment the inflatablechamber 830 can comprise two or more straight or curvilinearlongitudinally extending portions 860 having the same or differentinflated thicknesses. Such multiple longitudinally extending portions860, when inflated, can bias longitudinally extending, and laterallyspaced apart portions of the topsheet 738 into engagement with thewearer's external genitalia.

By way of example, the first material 300 can comprise about 300 mg ofpowdered Alka-Seltzer, and the packet 500 can contain about 4.0 ml ofwater. The chamber walls 832, 834 can be formed from theabove-referenced Tredegar Film C-8323 having a thickness of about 0.028mm (1.1 mil). The longitudinally extending portion 860 can have aninflated Z-direction thickness of about 1.27 cm (0.5 inch), a length 811of about 15.2 cm (6.0 inch), and a width 812 of about 1.27 cm (0.5inch). The laterally extending portions 862 can have an inflatedZ-direction thickness of about 0.635 cm (0.25 inch), a length 814 ofabout 1.27 cm (0.5 inch) and a width 813 of about 0.635 cm (0.25 inch).The inflated volume of chamber 830 can be about 28.7 cubic centimeters(1.75 cubic inches).

In FIGS. 10-12, the inflatable component 800 is shown joined to thebacksheet 742 and positioned intermediate the backsheet 742 and theabsorbent core 744. The inflatable component 800 is preferably joined tothe backsheet 742 so that laterally extending portions 862 can laterallystiffen the backsheet 742 and prevent lateral crushing of the sanitarynapkin 720 between the wearer's legs. The inflatable component ispreferably disposed between the backsheet 742 and the absorbent core 744so as not to interfere with the transfer of body exudates through thetopsheet 738 and into the absorbent core 742. In alternativeembodiments, the inflatable component 800 can be joined to the garmentsurface 723 of the backsheet 742, disposed intermediate layers of theabsorbent core 744, or disposed between the absorbent core 744 and thetopsheet 738.

While particular embodiments of the present invention have beenillustrated and described, various changes and modifications can be madewithout departing from the spirit and scope of the invention. It istherefore intended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A disposable absorbent article having a frontedge, a rear edge, longitudinal edges, and longitudinal and lateralcenterlines, the disposable absorbent article comprising: a liquidimpervious backsheet; a liquid pervious topsheet joined to thebacksheet; an absorbent core intermediate the topsheet and thebacksheet; a inflatable component having a sealed inflatable chamberdisposed intermediate the topsheet and the backsheet, the inflatablechamber inflatable from a first thickness to a second thicknesssubstantially greater than the first thickness; a predetermined amountof a first material disposed on the disposable absorbent article priorto use of the disposable absorbent article; a predetermined amount of asecond material disposed on the disposable absorbent article prior touse of the disposable absorbent article, wherein the second material isseparated from the first material by a breakable barrier, and whereinthe first and second materials are combinable at a time selected by auser of the article for providing inflation of the inflatable chamber.2. The disposable absorbent article recited in claim 1 wherein thesecond material comprises a liquid, and wherein the breakable barriercomprises a liquid impervious breakable packet containing the secondmaterial.
 3. The disposable absorbent article recited in claim 1 whereinat least one of the first and second materials evolves a gas uponcombining the first and second materials.
 4. The disposable absorbentarticle recited in claim 3 wherein the first and second materials aredisposed in a gas permeable envelope, and wherein the gas permeableenvelope is disposed within the inflatable component.
 5. The disposableabsorbent article recited in claim 3 wherein the first and secondmaterials combine to evolve carbon dioxide, and wherein one of the firstand second materials comprises water.
 6. The disposable absorbentarticle recited in claim 1 wherein the disposable absorbent articlecomprises a disposable diaper, wherein the topsheet comprises anaperture, and wherein the inflatable component comprises a spacerregistered with the aperture in the topsheet and disposed intermediatethe topsheet and the backsheet for maintaining a Z-direction fecal voidspace.
 7. The disposable absorbent article recited in claim 6 whereinthe spacer has an inflated shape comprising a generally closed figure.8. The disposable absorbent article recited in claim 6 wherein thespacer has an inflated shape comprising a generally U-shaped figureopening rearward and having longitudinally extending portions joined bya laterally extending portion.